Such a lock is used for temporary locking openings in motor vehicles or buildings with the aid of doors or tailgates. In the closed state of such a lock the rotary latch engages around a generally bow-shaped locking bolt also referred to as striker, which in case of a motor vehicle is mounted in most cases on the car body. When, as a result of being rotated from an open position, the rotary latch reaches a closed position, the rotary latch is then locked by means of the pawl. The rotary latch can then no longer be turned back in the direction of the open position and the locking bolt can no longer escape the locking mechanism. For opening, the pawl must be moved out of its detent position.
In the closed position, the blocking faces of the rotary latch and the pawl press against each other during latching. Both blocking faces are generally made of metal. To release the arrangement, one blocking face glides across the other face during which process frictional forces have to be overcome. There is therefore frictional contact between the two pawls.
The rotary latch and the pawl generally contain a hole for an axis extending through the hole, in order to rotatably mount the rotary latch and pawl. Either the rotatable component, i.e. the rotary latch or the pawl can be rotated around the axis or a rigid connection is provided between the rotary latch and the pawl and the axis, which in this case is itself rotatably mounted.
In order to prevent a pawl from being unintentionally moved out of its detent position, a blocking lever can be provided to block such a movement when the rotary latch is locked in a closed position.
A typical arrangement of a locking mechanism of a motor vehicle lock is disclosed in DE 103 20 457 A1. The arrangement and geometric shape of the rotary latch and pawl disclosed therein can also be applied to the present invention.
A locking mechanism of the invention can contain one or several of the above characteristics.
For reasons of stability the rotary latch and the pawl are generally essentially made of metal. At least the major part of these metal parts is covered by a plastic coating in order to minimize opening and closing noises. In FIG. 1 of DE 103 20 457 A1 experts can detect such a typical plastic coating of the rotary latch.
A lock thus contains a plurality of moveable and, in particular, rotatable components. To operate the moveable components it is necessary to provide lubricants at suitable points in order to minimize frictional losses and prevent any blocking of movement. It is thus, for instance, necessary to lubricate axes to maintain a reliable rotating movement. In addition it is also expedient to lubricate some areas, such as the blocking faces, pressed against each other for locking the rotary latch into place. As for unlocking, an associated pawl blocking face must release itself again from an associated rotary latch blocking face by a gliding movement. Such a gliding movement is enhanced by a lubricant. Also, blocking faces moved away from each other by a gliding movement, also advantageously reduce opening noises by providing a gliding agent between the blocking faces.